Vacuum cementing system

ABSTRACT

A vacuum cementing system has at least one cement powder cartridge and a container-opening system. The container-opening system has at least one container for at least one liquid and/or at least one powder, an opening device, and an outlet opening for applying a negative pressure. When a negative pressure is being applied, the opening device is mobile relative to at least a part of the at least one container. The vacuum cementing system has a means for connecting the cement powder cartridge to the at least one container and utilizes necessary vacuum for automatically opening the at least one container.

This is a divisional patent application of U.S. Ser. No. 13/808,452,filed on Jan. 4, 2013, which is a 371 of PCT/EP2011/002867 filed 10 Jun.2011 (international filing date), and claims the priority of GermanApplication No. 10 2010 026 497.0 filed 7 Jul. 2010.

The invention relates to a vacuum cementing system comprising acontainer-opening system for opening containers.

The invention provides vacuum cementing systems for opening monomerampoules for poly-methylmethacrylate bone cements (PMMA bone cements)prefilled with monomer liquid, as well as a device for storing andopening thereof that are made available to the medical user asfull-prepack vacuum cementing systems.

PMMA bone cements have been known for decades and are based on theground-breaking work of Sir Charnley (Charnley, J.: Anchorage of thefemoral head prosthesis of the shaft of the femur. J. Bone Joint Surg.42 (1960) 28-30.). The basic structure of PMMA bone cements has remainedthe same ever since. PMMA bone cements consist of a liquid monomercomponent and a powder component. The monomer component generallycontains the monomer, methylmethacrylate, and an activator(N,N-dimethyl-p-toluidine) dissolved therein. The powder componentconsists of one or more polymers that are made by polymerisation,preferably suspension polymerisation, based on methylmethacrylate andco-monomers, such as styrene, methylacrylate or similar monomers, aradio-opaquer, and the initiator, dibenzoylperoxide. Mixing the powdercomponent and the monomer component, a dough that can be shapedplastically is generated by swelling of the polymers of the powdercomponent in the methylmethacrylate. Mixing the powder component and themonomer component, the activator, N,N-dimethyl-p-toluidine, reacts withdibenzoylperoxide while forming radicals. The radicals thus formedtrigger the radical polymerisation of the methylmethacrylate. Uponadvancing polymerisation of the methylmethacrylate, the viscosity of thecement dough increases until the cement dough solidifies.

Polymethylmethacrylate bone cements can be mixed by mixing the cementpowder and the monomer liquid in suitable mixing beakers with the aid ofspatulas. This procedure is disadvantageous in that air inclusions maybe present in the cement dough thus formed and cause destabilisation ofthe bone cement later on. For this reason, it is preferred to mix bonecement powder and monomer liquid in vacuum mixing systems, since mixingin a vacuum removes air inclusions from the cement dough to a largeextent and thus achieves optimal cement quality (Breusch, S J et al.:Der Stand der Zementiertechnik in Deutschland. Z Orthop. 1999, 137:101-07). Bone cements mixed in a vacuum have clearly reduced porosityand thus show improved mechanical properties. A large number of vacuumcementing systems has been disclosed of which the following shall belisted for exemplary purposes: U.S. Pat. Nos. 5,624,184, 4,671,263,4,973,168, 5,100,241, WO 99/67015 A1, EP 1 020 167 A2, U.S. Pat. No.5,586,821, EP 1 016 452 A2, DE 36 40 279 A1, WO 94/26403 A1, EP 0 692229 A1, EP 1 005 901 A2, U.S. Pat. No. 5,344,232.

Vacuum cementing systems are used in the mixing of the PMMA bone cementin a vacuum in order to remove air inclusions from the cement dough.They are designed to produce a cement dough that is as homogeneous aspossible and largely free of bubbles.

Cementing systems are a refinement, in which both the cement powder andthe monomer liquid are already packaged in separate compartments of themixing systems and are mixed with each other only right beforeapplication of the cement in the cementing system (U.S. Pat. No.5,997,544, EP 0 692 229 A1, U.S. Pat. No. 6,709,149 B1). The issues ofsaid systems include the transfer of the monomer liquid into the cementpowder and the complete mixing of said two components in order to obtaina homogeneous cement dough that contains, in particular, no clusters ofcement powder that has not been wetted by the monomer liquid. In thefull-prepack mixing system, Optipac™ (Biomet Switzerland), which iscurrently commercially available in Europe, simple tubes, which areattached on the side in the lower part of the cartridge and puncturethrough the cartridge wall, are used to aspirate the monomer liquidapproximately from aluminium composite pouches into the centre of thecement powder through the action of a vacuum. Aluminium compositepouches are manually moved against the tubes in order to open them,whereby the tubes puncture through the wall of the pouches.

Aluminium composite pouches have been known for packaging and storingmonomer liquid for only a few years. Very good experience regarding thestorage properties of monomer liquid has been made with glass ampoules.Glass ampoules have been in use for decades with good success withconventional polymethylmethacrylate bone cements. Another advantage ofglass ampoules, aside from perfect sealing, is that they can be producedin large numbers at low prices. It is therefore reasonable to use glassampoules for packaging and storage of monomer liquid in prepack vacuumcementing systems.

DE 195 32 015 A1 describes a device for mixing and dispensingmulti-component products. This document proposes a device for theopening of ampoules that is based on a support socket about which anampoule holder can rotate being provided on the outside of the cementcartridge. The head of the ampoule is situated on the inside of thesupport socket. Rotating the ampoule holder about the support socket,the ampoule head is sheared off the ampoule body. The liquid can then betransferred from the ampoule into the cartridge through an opening inthe cartridge wall. WO 97/18031 A1 proposes a device, in which oneampoule is punctured on its bottom and the monomer liquid then can flowthrough the hollow mixing rod into the cement cartridge.

A system for the opening of ampoules in cementing systems is disclosedin EP 1 031 333 A1. In this system, a motion of the mixing rod against awedge-shaped device in the cartridge head moves the ampoule headobliquely against the ampoule axis, whereby the ampoule head is shearedoff the ampoule body. This is associated with a problem in terms of therelatively complex structure of the opening device and the danger of thewedge-shaped device getting lodged.

WO 2010/012114 A1 describes a device for the opening of ampoules.Analogous to DE 195 32 015 A1, this concerns a rotary mechanism forshearing off the head of the ampoule. The only difference from DE 195 32015 A1 is that a rotary socket is moved against the ampoule holderrather than the ampoule holder being moved against the rotary socket asin DE 195 32 015 A1.

In summary, it can be concluded that all prepack vacuum cementingsystems known to date contain monomer liquid containers that need to beopened manually. It would be more advantageous to have a forcedautomatic opening of the monomer liquid container proceed upon theapplication of vacuum on the cementing system. This would clearlysimplify the handling of the vacuum cementing systems for the medicaluser and render them safer.

The invention is based on the object to a full-prepack vacuum cementingsystem, in which monomer liquid containers are opened automaticallywithout manual action and thus the monomer transfer from a monomercontainer to a cement container can be triggered automatically.

Said object is met by a vacuum cementing system with at least one cementpowder cartridge and a container-opening system, whereby thecontainer-opening system comprises at least one container for at leastone liquid and/or at least one powder, an opening device, and an outletopening for applying a negative pressure, whereby when a negativepressure is being applied the opening device is mobile relative to atleast a part of the container, and the vacuum cementing system comprisesa means for connecting the cement powder cartridge to the container, andwhereby the vacuum necessary for a cement dough with a low bubblecontent is additionally used for automatically opening the container.

It is of advantage if the container is arranged within a chamber and theoutlet-opening is connected to the chamber.

In this context, it may be provided that the pressure difference movesan opening device as part of the container-opening system relative to atleast one container, whereby the opening device is supported in thecontainer-opening system like in a bearing such as to be mobile and/orthe container is supported in the container-opening system like in abearing such as to be mobile.

Moreover, the invention can provide a mobile plunger to be shifted inthe container-opening system in such manner that the container orcontainers is or are opened through the motion of the plunger.

It is of advantage in this context if at least a part of the containeris fractured, broken-off, cut open, cut off or pierced through themotion of the plunger such that the plunger acts as opening device.

Alternatively, it can be advantageous that the plunger takes up thecontainer and that the motion of the plunger presses the container ontoa part of the opening device, whereby the container is thus fractured,broken open, cut open or pierced.

The invention can provide a lever as opening device to be rotated ortilted through the motion of the plunger containing the container, andat least a part of the container to be broken off, cut open or piercedthrough the rotation of a lever arm of the lever.

Another alternative method according to the invention has the motion ofthe plunger tilting the container, whereby a part of the containerbecomes fixed in place in the container-opening system in suitablemanner for the fixed part of the container to be broken off.

Another alternative results if at least a part of a wall of thecontainer is moved relative to a mandrel that is attached to thecontainer-opening system and acts as opening device and, as a result,cuts open or pierces and thus opens the wall of the container.

The invention can just as well provide that the container or containerscontain a liquid, in particular a monomer liquid, and/or a powder, inparticular a cement powder, whereby the content exits from the containerafter opening through the action of the negative pressure, in particulara vacuum, and is subsequently mixed with a powder, in particular acement powder, or a liquid, in particular a monomer liquid, through theaction of the negative pressure, in particular a vacuum.

In this context, the invention can provide the mixture to be pressed ormade to leak from an applicator, preferably by means of anover-pressure.

The invention also relates to a container-opening system that issuitable for implementing a method of this type, comprising at least onecontainer for at least one liquid and/or at least one powder, an openingdevice and an outlet opening for application of a negative pressure,whereby the opening device is mobile relative to at least one part ofthe container upon the application of a negative pressure.

In this context, the invention can provide the container and/or theopening device to be supported in the container-opening system like in abearing such as to be mobile.

Moreover, the invention can provide the container-opening system tocomprise a plunger that is supported like in a bearing such as to bemobile and, in particular, is cylindrical in shape.

In addition, it can be advantageous for the opening device to comprisethe mobile plunger.

A refinement of the invention provides the mobile plunger to comprise afork-shaped guidance for guiding a part of the container to be brokenopen and/or the interior of the plunger to be bevelled.

The invention can also provide the mobile plunger to be a hollow bodythat is closed on one side and has the container arranged in it.

In this context, it is advantageous for the opening device to comprise alever that can be rotated within the container-opening system or tocomprise a fin on the bottom of the hollow body that is closed on oneside.

An alternative embodiment provides the container to comprise apreferably flexible wall and the opening device to be a mandrel or ablade, whereby the container is arranged in the container-opening systemsuch as to be mobile and/or the wall can be deformed.

The invention can just as well provide for the container to comprise aliquid that contains a monomer component, preferably a polymerisablemonomer such as, for example, methylmethacrylate, and an activatordissolved therein.

The object is also met by a vacuum cementing system comprising acontainer-opening system according to the invention, comprising at leastone cement powder cartridge, whereby the container of thecontainer-opening system preferably is an ampoule, in particular amonomer liquid container, and the vacuum cementing system comprises ameans for connecting the cement powder cartridge to the ampoule.

In this context, the invention can provide the cement powder cartridgeto comprise at least one mixing organ, in particular a feed plunger.

The invention can just as well provide a static mixer to be arranged atan application opening of the vacuum cementing system.

Moreover, the invention can provide the cement powder cartridge tocontain a powder comprising one or more polymers, in particular based onmethylmethacrylate and comonomers.

Direct opening of a container through the pressure difference shall beunderstood to mean that the external pressure moves a mobile means, forexample a plunger, relative to the container and relative to the entirecontainer-opening system and thus opens the container by mechanicalmeans, i.e., for example, through breaking open, cutting open orpiercing into a part of the container and/or of a container wall. Forthis purpose, the means for opening of the container is supported in thecontainer-opening system like in a bearing such as to be mobile. Thedifferential pressure therefore acts on the opening means resulting in amotion of the means.

Direct opening is evident if the pressure difference presses a containeror a part of a container onto a static opening device. In this context,the differential pressure acts directly on the mobile container suchthat said container moves against the container-opening system. For thispurpose, the container is supported in the container-opening system likein a bearing such as to be mobile. The container is then pushed orpressed onto an opening device that is connected to thecontainer-opening system and opened mechanically by breaking open,cutting open or piercing into a part of the container and/or of acontainer wall.

Indirect opening is also evident if both the container and the openingdevice move, i.e. if both are supported in the container-opening systemlike in a bearing such as to be mobile.

The invention is based on the surprising finding that a vacuum in vacuumcementing systems can be put to use not only for removing air inclusionsfrom the cement dough, but also for the opening of containerscontaining, for example, a monomer. Accordingly, the vacuum that isneeded anyway in vacuum cementing systems for producing a cement doughwith a low bubble content is, in addition, used for automatic opening ofcontainers, for example monomer liquid containers. Generating a negativepressure in the cementing system, the pressure difference as compared tothe surroundings thus generated is used to drive an automatic mechanicalopening system. The negative pressure effects a relative motion of anopening device, such as, for example, a plunger, against the container,whereby a mechanical force is made to act on the container as a resultof the relative motion. The action of said force opens the container andreleases its content, for example a monomer required for the productionof bone cement.

In the scope of the invention, the term, container, shall be understoodto preferably mean glass ampoules, plastic ampoules, aluminium ampoules,and plastic composite pouches, including aluminium composite pouches.

In the following, exemplary embodiments of the invention are illustratedthrough ten schematic drawings. In the figures:

FIG. 1: shows a schematic cross-sectional view in longitudinal directionof a container-opening system according to the invention with a closedcontainer;

FIG. 2: shows a schematic top view onto a plunger having a fork-shapedguidance as opening device for a container-opening system according tothe invention;

FIG. 3: shows a schematic front view of the plunger according to FIG. 2;

FIG. 4: shows a schematic perspective view of the plunger according toFIG. 2;

FIG. 5: shows a schematic cross-sectional view in longitudinal directionof an alternative container-opening system according to the inventionwith a closed container;

FIG. 6: shows a schematic cross-sectional view in longitudinal directionof a third container-opening system according to the invention with aclosed container;

FIG. 7: shows a schematic cross-sectional view in longitudinal directionof a fourth container-opening system according to the invention with aclosed container;

FIG. 8: shows a schematic cross-sectional view in longitudinal directionof a fifth container-opening system according to the invention with aclosed container;

FIG. 9: shows a schematic cross-sectional view of a vacuum cementingsystem according to the invention; and

FIG. 10: shows a schematic cross-sectional view in longitudinaldirection of a sixth container-opening system according to the inventionwith a closed container.

Examples for vacuum cementing systems are illustrated in the followingdescription of figures.

FIG. 1 shows a schematic cross-sectional view of a container-openingsystem (1) according to the invention that has a container (2) arrangedin it in the form of an ampoule. The container (2) comprises a containerhead (3) and, according to FIG. 1, a container body situated above thehead. A pre-determined breakage site is present between the containerhead (3) and the container body.

The container is arranged in a chamber (4) of the container-openingsystem (1) and is positioned by means of two connectors (5). An outletopening (6) is provided in the chamber (4) below the container head (3).The upper side of the chamber (4) is closed through a lid (7). The lid(7) is connected to the chamber (4) by means of a thread or any otherclosure mechanism. The container-opening system (1) can be incorporatedor integrated into another device that is shown here by means of theopen walls (8).

A cylindrical opening is provided in the walls of the chamber (4) in theregion of the container head (3) and has a cylindrical plunger (9)arranged in it that is mobile along its axis of symmetry. The side ofthe plunger (9) that extends into the inside of the chamber (4) isbevelled. The bevelling is to ensure that the container head (3) breaksoff the container body easily when the plunger (9) is pushed into theinside of the chamber (4). The bevelling of the connector (5) situatedopposite from the plunger (9) serves the same purpose. Both measures areintended to focus and enhance the force acting through the plunger (9)on the breakage zone.

The walls of the chamber (4) and the lid (7) are resistant to pressure,i.e. retain their shape even when a vacuum is generated on the inside ofthe chamber (4). The plunger (9) is lodged in a gas-tight press-fit inthe opening of the walls of the chamber (4).

The method according to the invention can be implemented, for example,as follows: Firstly, a negative pressure is applied at the outletopening (6). This establishes a negative pressure on the inside of thechamber (4) as well. The difference in pressure between the inside ofthe chamber (4) and the exterior surroundings of the chamber (4) causesa larger pressure, and therefore a larger force, to act on the surfaceof the plunger (9) facing outward than on the surface of the plunger (9)facing inward. The plunger (9) thus experiences a resultant force thatdrives it into the inside of the chamber (4). Once the static frictionof the plunger (9), which is in a press-fit, is overcome through theresultant force, the plunger (9) moves to the inside of the chamber (4).Lastly, the plunger (9) is to hit against the container head (3) andshear it off. This opens the container (2). The content of the container(2) flows out of the container and through the outlet opening (6) toexit from the container-opening system (1).

Since modern vacuum cementing systems always generate a vacuum anyway,for example in order to mix a monomer liquid and a bone cement in avacuum, said vacuum can concurrently be utilised to open the sterileclosed container (2), in which the monomer liquid and/or the bone cementpowder is/are situated. For example glass ampoules are suitable andcustomary containers (2) for the monomer liquid and/or the bone cement.

The static friction of the plunger (9) in the opening of the chamber (4)and/or the stability of the breakage zone of the container (2) or thecross-section of the plunger (9) can be adjusted in suitable manner inthis context such that the container (2) and/or the glass ampoule isbeing opened only when the negative pressure in the chamber (4) issufficient for a sufficiently bubble-free mixture to be generated frommonomer liquid and bone cement.

The opening device in this exemplary embodiment is the plunger (9) thatis supported like in a bearing such as to be mobile.

FIGS. 2, 3, and 4 show various views of schematic depictions of aplunger (19) with an alternative design for alternativecontainer-opening systems according to the invention (not shown). Theplunger (19) that is to function as opening device for containerscomprises a fork-shaped guidance consisting of two fins (20) and furthercomprises a bevelled projecting plate (21). The fork-shaped guidance(20) is to define the motion of the plunger (19) relative to a containerhead. A suitable container for this purpose has a tapering between thecontainer head and the container body that can be engaged by thefork-shaped guidance (20).

The plate (21) can be used to either break off and/or shear off thecontainer head or the edges of the plate (21) are sufficiently sharp asto be capable of cutting through the walls of a container. The purposeof the fork-shaped guidance (20) and of the plate (21) is to render theprocess of opening more reproducible and more accurate. The interveningspace between the two fins (20) can taper in the direction of theplunger (19) in order to allow for a container head to be severed whenthe plunger (19) moves. Then, there is no longer a need to have theplate (21) present.

FIG. 5 shows another schematic cross-sectional view of a secondalternative container-opening system (31). The container-opening system(31) comprises a container (32) having a container head (33). Thecontainer (32) can contain, for example, a liquid. The container (32) issituated on the inside of a plunger (39) which in turn is lodged inmobile manner in a chamber (34). An outlet opening (36) is situated atthe lower end of the chamber (34) below the container head (33). Theentire container-opening system (31) is integrated into a device shownby means of open walls (38), such as, for example, a vacuum cementingsystem according to the invention.

The inside of the chamber (34) has a lever (40) situated in it that issupported like in a bearing such that it can be rotated and serves asopening device for the container (33) and has its first lever arm (41)supported at the walls of the chamber (34), whereby a second lever arm(42) loosely leans against the container head (33) in the form of a finthat branches perpendicularly off the first lever arm (41).

In a method according to the invention, a vacuum is generated in thechamber (34) by means of pumping the air out through the outlet opening(36). Due to the differential pressure between the inside of the chamber(34) and the surroundings of the container-opening system (31), themobile plunger (39) containing the container (32) is pulled into thechamber (34). This concurrently leads to a rotation of the lever (40)through which a force is exerted on the container head (33) through thesecond lever arm (42). As soon as this force is sufficiently large, thecontainer head (33) is fractured or broken off the container (32).

The liquid stored in the container (33) can then exit from the container(33) and flow out through the outlet opening (36) out of thecontainer-opening system (31). Subsequently, the liquid can be guided toa cement powder through the negative pressure that is being applied tothe outlet opening (36) and mixed with the cement powder in the vacuumcementing system (indicated by the open walls (38)).

FIG. 6 shows a schematic cross-sectional view of a thirdcontainer-opening system (51) according to the invention. Like in thesecond exemplary embodiment, a container (52) is situated on the insideof a plunger (59) that is arranged in a gas-tight opening of a chamber(54) such as to be mobile. An outlet opening (56) is situated in thechamber (54) opposite from a container head (53) and can be used toapply a negative pressure to the chamber (54).

The plunger (59) comprises, on one side, a connector (55) for bracketingthe container (52), and, on the other side, a wedge-shaped fin (63)having a bevelling on the side facing the container (52). A lever (60)that is provided in longitudinal direction with respect to the container(52) is situated in the chamber (54). The lever (60) is firmly connectedto the walls of the chamber (54) in the region of the outlet opening(56) by means of a first lever arm (61) and comprises a bevelling on theside facing away from the container (52). The first lever arm (61) ismade of an elastic, easily deformable material.

When a vacuum is applied to the chamber (54), the plunger (59) and thecontainer (52) contained therein are pulled into the inside of thechamber (54). The bevelling of the wedge-shaped fin (63) slides betweenthe walls of the chamber (54) and the bevelling of the lever (60). Thispushes the lever (60) against the side of the container head (53) uponwhich the same breaks off the container (52). In addition, the tip ofthe lever (60) can puncture or cut into the pre-determined breakage siteof the container (52) moving into the chamber (54).

Accordingly, the invention can provide the plunger (59) to possess awedge-shaped fin (63) that is formed parallel to the ampoule axis,whereby a bevelling is provided on the side facing the ampoule side, anda lever (60) is situated in the chamber (54) that is formed inlongitudinal direction with respect to the ampoule axis and has itsupper lever end being situated adjacent to the ampoule head (53) such asto be freely mobile, whereby the lever (60) possesses a bevelling on theside facing away from the ampoule axis and the lever (60) is connectedin mobile manner to the chamber (54) through the lower lever end (61).

Applying a vacuum, the fin (63) moves jointly with the plunger (59) inthe direction of the ampoule head (53), whereby the bevelling of the fin(63) presses onto the bevelling of the lever (60). The lever (60) isfixed in place at its lower lever end (61) and its mobile upper leverend is forced to perform a rotary motion against the ampoule head (53).This causes the ampoule head (53) to break off the ampoule body. In thisindirect opening of the container, the wedge (63) acts jointly with thelever (60) as opening device in the scope of the present invention.

FIG. 7 shows another schematic cross-sectional view of acontainer-opening system (71) according to the invention having aplunger (79) that is arranged in a chamber (74) such as to be mobile andis situated in an opening on the upper side of the chamber (74). Theouter walls of the plunger (59) seal against the opening of the chamber(74) in gas-tight manner. A container (72) is positioned within thechamber (74) by means of connectors (75) at the walls of the chamber(74) and through an outlet opening (76) in the bottom of the chamber(74). A container head (73) of the container (72) is lodged in theoutlet opening (76) and is connected to the container body by means of apre-determined breakage site.

The connectors (75) essentially consist of a solid material and supportthe container (72) essentially only in spots. However, the provision ofsupport along contact lines or surfaces is feasible as well. The contactsites of the connectors (75) define a centre of rotation about which thecontainer (72) can be tilted.

The mobile plunger (59) is a hollow body having a closed end on oneside. The internal cross-section of the plunger (79) is larger than theexternal cross-section of the container (72). A fin (80) in the form ofa bevelling is situated on the inside of the plunger (79) and isarranged at the closed end and at a cylinder wall of the plunger (79).Regions of the container (72) project into the plunger (79).

The shape of the container head (73) and the shape of the outlet opening(76) are matched to each other such that they do not close with eachother in form-fitting manner, i.e. the shape of the container head (73)does not perfectly match the shape of the outlet opening (76). This isto ensure that the outlet opening (76) does not become closed completelyby the container head (73).

As a result, the atmosphere can be evacuated from the inside of thechamber (74) through the outlet opening (76) to establish a negativepressure in the chamber (74). The normal pressure in the surroundings ofthe container system (71) then pushes the plunger (79) in the directionof the outlet opening (76).

The fin (80) at the closed end of the plunger (79) is then pushedagainst an upper corner of the container (72) and the container (72) istilted when the plunger (79) is pushed-in further. Since the containerhead (73) cannot follow the tilting motion of the container (72), itfractures or breaks off and the content of the container (72) isreleased through the outlet opening (76).

Accordingly, the fin (80) and the plunger (79) as well as the bracketingof the container head (76) jointly with the connectors (75) act asopening device in the scope of the present invention. Evidently, it isnot that easy in this case to identify which parts form the openingdevice. Ultimately, a concerted action of different components isrequired in most cases to open the container. Said components then formthe opening device in the scope of the present invention.

FIG. 8 shows another embodiment according to the invention of acontainer-opening system (91) for a method according to the invention.In this exemplary embodiment, the container (92) is again opened bybreaking off or fracturing a container head (93) that is supported in anoutlet opening (96) of a chamber (94). The chamber (94) is closedthrough a lid (97). The lid (97) seals the chamber (94) in gas-tightmanner and in vacuum-tight manner.

The entire container-opening system (91) can be integrated into a vacuumcementing system (indicated through the open walls (98)).

An opening of the walls of the chamber (94) has a plunger (99) situatedin it that is mobile in the opening and seals the opening in gas-tightmanner. The plunger (99) is attached to the container (92) through abracketing (100) in the form of a cuff.

In this case, the outlet opening (96) is not arranged in the centre ofthe chamber (94). As a result, the container (92) is situated tightlyagainst the external walls of the chamber (94) on the side having theplunger (99), whereas there is still space to the walls of the chamber(94) on the opposite side.

What this attains is that the container (92) is rotated about an axis inthe connection of the container head (92) to the container body when theplunger (99) penetrates into the chamber (94). Since the container head(91) cannot follow this motion, it is being broken off or fractured.This opens the container (92). The content of the container (92) canexit through the outlet opening (96) and is thus available to a vacuumcementing system that is connected to the container-opening system (91),to be mixed with another component.

According to the invention, the plunger is again moved due to a negativepressure being established in the chamber (94). For the outlet opening(96) to be useful, it is important that the container head (93) and thecontainer (92) do not seal the outlet opening (96). Only this ensuresthat the outlet opening (96) can be used both for evacuating the chamber(94) and for discharging the content of the container (92).

Alternatively, a second free opening can be provided in the chamber (94)adjacent to the outlet opening (96) and allow the chamber (94) to beevacuated and the content of the container (92) to exit from the chamber(94). Rather than being supported in the outlet opening (96), it isfeasible to simply provide a separate fastening for the container head(93) in the chamber (94) that is not connected to the region outside thechamber.

In this case, the opening device is formed by the plunger (99), thebracketing (100), and the bracketing of the container head (93), i.e.the outlet opening (96), and indirectly forces the container (92) toopen.

FIG. 9 shows a vacuum cementing system (110) comprising acontainer-opening system (111) comprising a liquid-filled glass ampouleas container (not shown) that is connected to a cement powder cartridge(113) through a connecting means (112), for example a tubing. The cementpowder cartridge (113) is connected to a foot part (115) of the vacuumcementing system (110) through a fastening means (114), such as, forexample, a thread. The cement powder cartridge (113) comprises a feedplunger (116) that can be used to expel the content of the cartridge(113) from the vacuum cementing system (110) and/or to apply theready-mixed cement.

A vacuum is used initially to open the glass ampoule in thecontainer-opening system (111), as shown in the other figures. Thevacuum aspirates the liquid from the container through the connectingmeans (112) into the cement powder cartridge (113) where it mixes withthe cement. The mixture can be applied by means of the feed plunger(116). A static mixer (not shown) can be provided in the applicationopening (not shown) of the vacuum cementing system (110) to attain morethorough mixing of the liquid and the cement.

The method according to the invention and the vacuum cementing system(111) according to the invention are particularly advantageous andwell-suited for PMMA bone cements, whereby a monomer component (forexample containing methylmethacrylate and an activator) is used asliquid and a bone cement powder consisting of one or more polymers (forexample based on methyl-methacrylate and comonomers) is used as powdercomponent and/or these are contained in the container and the cementpowder cartridge (113).

FIG. 10 shows another vacuum cementing system (130) comprising acontainer-opening system (131) that is somewhat different from the otherexemplary embodiments. The container-opening system (131) comprises acontainer (132) in the form of a film pouch containing a liquid, and atube (140), whereby a mandrel (141) having a blade is arranged on theinside of the tube (140). One wall of the film pouch (132) touchesagainst the tube (140) in gas-tight manner. The mandrel (141) isattached to one of the tube walls. The tube (140) corresponds, to alimited extent, to the outlet openings (6, 36, 56, 76, 96) and theconnecting means (112) in other exemplary embodiments.

A cement powder cartridge (133) is connected to the tube (140) on theside of the tube (140) that is opposite from the container (132). A feedplunger (136) is situated on the inside of the cement powder cartridge(133) and can be used to expel the content of the cement powdercartridge (133) from an application opening (142). A connector of theapplication opening (142) has a fastening means (134) attached to it inthe form of a thread to which an applicator tip having a static mixer(not shown) can be connected. A vacuum connection (143) to which avacuum pump and/or a source of negative pressure can be attached isarranged at the upper end of the cement powder cartridge (133).

In this embodiment of the method according to the invention, firstly, anegative pressure is applied to the vacuum connection (143). The filmpouch (132) is pulled into the inside of the tube (140) and slit openthrough the blade of the mandrel (141). The content of the container(132) is aspirated into the tube (140). Simultaneously, the feed plunger(136) is pulled upwards. And lastly, the liquid can be passed from thecontainer (132) through the tube (140) into the cement powder cartridge(133). In this location, it mixes with a cement powder that is containedin the cement powder cartridge (133).

Pressing by hand on the feed plunger (136) or applying a positivepressure to the vacuum connection (143), the feed plunger cansubsequently be pushed in the direction of the application opening (142)as before. In the process, the mixture of cement powder/liquid isexpelled from the application opening (142).

This embodiment according to FIG. 10 attains direct opening of thecontainer (132). The container (132) itself moves by its flexible wall,which touches against the cross-section of the tube (140), onto theopening device, namely the mandrel (141), that is firmly connected tothe container-opening system. It would also be conceivable that thecontainer (132) has rigid container walls and is arranged in the tube(140) itself. For it to be aspirated onto the mandrel (141), it needs toseal against the walls of the tube (140) in gas-tight manner like theplunger (9, 39, 59, 79, 99) in the other exemplary embodiments.

The scope of the invention also includes the wall of the container (132)tearing autonomously in the region of the tube (140) due to the internalpressure of the container (132). A valve preventing reflux of the cementinto the tube (140) and into the container (132) can be provided insidethe tube (140).

Applicable to all exemplary embodiments, a sieve and/or a filter (notshown) can be arranged below the outlet opening (6, 36, 56, 76, 96)and/or in the tube (140), and can be used to retain fragments and/orresidues of the container (2, 32, 52, 72, 92, 132) that may be producedwhen the container (2, 32, 52, 72, 92, 132) is cut open, cut off orfractured and/or when the container head (3, 33, 53, 73, 93) is beingbroken off.

Preferably, the container (2, 32, 52, 72, 92, 132) is an ampoule, inparticular a glass ampoule.

A method according to the invention for the opening of ampoules invacuum cementing systems can also be characterised in that a vacuum ofan absolute pressure larger than or equal to 70 mbar acting on at leastone plunger slides the plunger relative to one or more monomer liquidcontainer(s), and in that the monomer liquid container(s) is or arethereby opened, whereby the opening proceeds through piercing and/orcutting open and/or breaking open.

The scope of the invention also includes devices comprising at least onecement powder cartridge (113, 133) having at least one mixing organ(116, 136), an ampoule (1, 31, 51, 71, 91, 111, 131) as monomer liquidcontainer, a connecting means (112) for connecting the cement powdercartridge (113, 133), an ampoule container formed in at least onechamber (4, 34, 54, 74, 94) and at least one plunger (9, 19, 39, 59, 79,99), whereby

a) at least one plunger (9, 19, 39, 59, 79, 99) is arranged such that atleast one chamber (4, 34, 54, 74, 94) is sealed from the externalsurroundings which are exposed to normal pressure;

b) the plunger (9, 19, 39, 59, 79, 99) is connected to the chamber (4,34, 54, 74, 94) in gas-tight manner;

c) the cross-section of the chamber (4, 34, 54, 74, 94) is suitablyadapted such that the plunger (9, 19, 39, 59, 79, 99) can be slidthrough the chamber (4, 34, 54, 74, 94) along the plunger axis;

d) the plunger (9, 19, 39, 59, 79, 99) is arranged such that it can beslid along the plunger axis;

e) the plunger (9, 19, 39, 59, 79, 99) can be connected by means of itsside facing the chamber (4, 34, 54, 74, 94) to at least one site of theampoule (2, 32, 52, 72, 92, 132) that is arranged in said chamber (4,34, 54, 74, 94) in a non-positive fit-like or positive fit-like manner;

f) the chamber (4, 34, 54, 74, 94) contains at least one outlet opening(6, 36, 56, 76, 96) for fluids; and/or

g) the plunger (9, 19, 39, 59, 79, 99) can be moved along its plungeraxis through changes of the relationship between the pressure inside thechamber (4, 34, 54, 74, 94) and the ambient pressure and thus exerts aforce on the ampoule (2, 32, 52, 72, 92, 132).

The invention can also provide the plunger (9, 19, 39, 59, 79, 99) to bearranged perpendicular to the ampoule axis and to be provided, at theplunger side facing in the direction of the inside of the chamber (4,34, 54, 74, 94), to be perpendicular or oblique to the wall surface ofthe chamber (4, 34, 54, 74, 94), whereby the plunger side can have asmooth surface or a grooved surface. Exposed to a vacuum, the plunger(9, 19, 39, 59, 79, 99) moves in the direction of the ampoule head (3,33, 53, 73, 93) and shears it off against the ampoule body.

The invention can also provide, if applicable, a fork-shaped guidance(20) to be attached on the inside of the plunger (9, 19, 39, 59, 79,99), whereby the distance of the fins of the guidance (20) is equal toor larger than the diameter of the ampoule (2, 32, 52, 72, 92, 132) inthe breakage zone. The guidance (20) can fix the ampoule (2, 32, 52, 72,92, 132), between the ampoule head (3, 33, 53, 73, 93) and the ampouleshoulder, in place with respect to perpendicular motions along theampoule axis. This ensures that the ampoule (2, 32, 52, 72, 92, 132)cannot get out of the way when the plunger (9, 19, 39, 59, 79, 99) isshifted onto the ampoule head (3, 33, 53, 73, 93). Fracturing of theampoule (2, 32, 52, 72, 92, 132) is thus made more reliable.

The invention can just as well provide the plunger (9, 19, 39, 59, 79,99) parallel to the ampoule axis in the form of a hollow cylinder (39,59, 79) that is closed on one side and takes up the ampoule (2, 32, 52,72, 92, 132) and can be shifted in the direction of the inside of thechamber (4, 34, 54, 74, 94) either jointly with the ampoule (2, 32, 52,72, 92, 132) or separate from the ampoule (2, 32, 52, 72, 92, 132).

Just as well, a device according to the invention can be characterisedin that the plunger (9, 19, 39, 59, 79, 99) can be shifted onto a firstlever end of a lever (40) that is arranged in the chamber (4, 34, 54,74, 94) and is arranged oblique to the ampoule axis below the ampoulehead (3, 33, 53, 73, 93) and possesses at least one fin (42)perpendicular to the lever axis, whereby the fin (42) is orientedopposite from the ampoule head (3, 33, 53, 73, 93) and the first leverend of the lever (40) is situated freely in the chamber (4, 34, 54, 74,94) and a second lever end (41) is connected to the chamber (4, 34, 54,74, 94) such that it can rotate.

When the plunger (9, 19, 39, 59, 79, 99) is pushed onto the first leverend by applying a vacuum, the lever (40) performs a rotary motion,whereby the fin (42) is forced to also perform a rotary motion and thusa shearing motion against the ampoule head (3, 33, 53, 73, 93). Thisshears the ampoule head (3, 33, 53, 73, 93) off the ampoule body.

Another embodiment according to the invention is characterised in thatthe plunger (79) is provided as a hollow cylinder (79) that is closed onone side and possesses a fin (80) at the closed side of the cylinder, inthat the fin (80) arranged in the direction of the open hollow cylinder(79) is bevelled, whereby the bevelling faces in the direction of thelongitudinal axis of the plunger (79) and the largest slope of thebevelling is within the radius of the ampoule cross-section, and in thatthe ampoule (72) is arranged in the ampoule container (the chamber (74))in such manner that the ampoule body has a sufficient distance from theinternal wall of the ampoule container (74) such that the ampoule head(73) can be sheared off, i.e., for example, has a distance of more than3 mm, whereby the ampoule head (73) is fixed in place in a non-elasticfastening hollow cylinder that has an internal diameter that is equal toor larger than the ampoule head (73).

The application of a vacuum moves the hollow cylinder (79) in thedirection of the ampoule head (73). The fin (80) moves along in thedirection of the ampoule head (73) concurrently. Due to its bevelling,the fin (80) presses the ampoule body perpendicularly with respect tothe ampoule axis. The ampoule head (73) is fixed in place againsttwisting in a fastening hollow cylinder. This breaks the ampoule bodyoff the ampoule head (73). Due to the lever effect, a minimal forceacting on the end of the ampoule body opposite from the ampoule head(73) is sufficient to break the ampoule head (73) off the ampoule body.

The scope of the invention also includes a prepack vacuum cementingsystem, in which a foot part (115) has a cement powder cartridge (113,133) having at least one mixing organ (116, 136) and a vacuum connection(143), an ampoule container (1, 31, 51, 91, 111, 131), a means (112,140) for connecting the cement powder cartridge (113, 133) to theampoule container (111), and at least one chamber (4, 34, 54, 74, 94)having a plunger (9, 19, 39, 59, 79, 99) arranged on it, whereby theplunger (9, 19, 39, 59, 79, 99) is provided as a hollow cylinder andtakes up the ampoule (2, 32, 52, 72, 92, 132), whereby the plunger (9,19, 39, 59, 79, 99) can be pushed onto a first lever end of a lever (40)that is arranged in the chamber (4, 34, 54, 74, 94) such as to beoblique to the ampoule axis and below the ampoule head (3, 33, 53, 73,93) and which possesses at least one fin (42) perpendicular to the leveraxis, whereby the fin (42) is oriented opposite from the ampoule head(3, 33, 53, 73, 93) and the first lever end of the lever (40) issituated freely in the chamber (4, 34, 54, 74, 94) and a second leverend (41) is connected to the chamber (4, 34, 54, 74, 94) such that itcan be rotated.

The scope of the invention also includes a prepack vacuum cementingsystem comprising a foot part (115), a cement powder-filled cementpowder cartridge (113, 133) having at least one mixing organ (116, 136),for example a feed plunger, and a vacuum connection (143), a monomerliquid-filled ampoule (2, 32, 52, 72, 92, 132), a means (112, 140) forconnecting the cement powder cartridge (113, 133) to the ampoulecontainer (1, 31, 51, 91, 111, 131), and at least one chamber (4, 34,54, 74, 94) having a plunger (9, 19, 39, 59, 79, 99), whereby theplunger (9, 19, 39, 59, 79, 99) possesses a wedge-shaped fin (63) thatis provided parallel to the ampoule axis, whereby a bevelling isarranged on the side facing the ampoule side, and a lever (60) that isprovided in the longitudinal direction relative to the ampoule axis issituated in the chamber (4, 34, 54, 74, 94) and has a lever end that issituated freely mobile adjacent to the ampoule head (3, 33, 53, 73, 93),whereby the lever (60) possesses a bevelling on the side facing awayfrom the ampoule axis, and in that the lever (60) is connected in mobilemanner to the chamber (4, 34, 54, 74, 94) by means of the lower leverend (61).

A variant of the prepack vacuum cementing system is characterised inthat a foot part (115) has a cement powder-filled cement powdercartridge (113, 133) having at least one mixing organ (116, 136) and avacuum connection (143), a monomer liquid-filled ampoule (2, 32, 52, 72,92, 132), a means (112, 140) for connecting the cement powder cartridge(113, 133) to the ampoule container (1, 31, 51, 91, 111, 131), and atleast one chamber (4, 34, 54, 74, 94) having a plunger (9, 19, 39, 59,79, 99) arranged on it, whereby the plunger (9, 19, 39, 59, 79, 99) isprovided as a hollow cylinder that is closed on one side and possesses afin (80) at the closed side of the cylinder, in that the fin (80) thatis arranged in the direction of the open hollow cylinder is bevelled,whereby the bevelling faces in the direction of the longitudinal axis ofthe plunger (9, 19, 39, 59, 79, 99) and the largest slope of thebevelling is within the radius of the ampoule cross-section, in that theampoule (2, 32, 52, 72, 92, 132) is arranged in the ampoule container(1, 31, 51, 91, 111, 131) in such manner that the ampoule body has adistance of more than 3 mm from the internal wall of the ampoulecontainer (1, 31, 51, 91, 111, 131), and in that the ampoule head (3,33, 53, 73, 93) is supported like in a bearing in a non-elastic hollowcylinder.

A design variant of the device is characterised in that the plunger (79)is arranged such that it can be pushed perpendicularly or approximatelyperpendicularly against the ampoule body, whereby the ampoule body isfixed in place to a plunger (99) through a fixation (100). The fixation(100) can be provided, for example, to be fork-shaped. One of thepurposes of having the fixation (100) is to ensure optimal transmissionof force from the plunger (99) to the ampoule body. Another purpose isthat the fixation (100) stabilises the ampoule (92) during transport.

According to another embodiment, the prepack vacuum cementing systemcontains a foot part (115), a cement powder-filled cement powdercartridge (113, 133) having at least one mixing organ (116, 136) and avacuum connection (143), a means (112, 140) for connecting the cementpowder cartridge (113, 133) to the ampoule container (1, 31, 51, 91,111, 131), one monomer liquid-filled ampoule (2, 32, 52, 72, 92, 132),and at least one chamber (4, 34, 54, 74, 94) having a plunger (9, 19,39, 59, 79, 99), whereby the plunger (9, 19, 39, 59, 79, 99) is arrangedsuch that it can be pushed perpendicularly or essentiallyperpendicularly in or above the ampoule container (1, 31, 51, 91, 111,131), whereby the ampoule body is fixed in place to a plunger (99) bymeans of a bracketing (100).

The scope of the invention also includes a device comprising at leastone cement powder cartridge (113, 133) having at least one mixing organ(116, 136), at least one film pouch (132) as monomer liquid container,at least one chamber (4, 34, 54, 74, 94), and at least one plunger (9,19, 39, 59, 79, 99). Said device is characterised in that a tube (140)is provided, whereby a mandrel (141) having a tip or a mandrel (141)having a blade is arranged on the inside of the tube (140) and has itstip situated below the edge of the tube (140), and at least one externalside of the film pouch (132) rests on the edge of the tube (140), and inthat at least one vacuum connection (143) is present, whereby the vacuumconnection is concurrently provided as opening for fluids.

Said device is based on the film pouch (132) touching against the edgeof the tube (140) being pulled into the tube (140) upon the applicationof a vacuum. Its deformability and flexibility allow the film pouch tobe pulled in. While it is being pulled into the tube (140), the filmpouch (132) is pierced open or cut open by means of the mandrel (141)having the tip or the mandrel (141) having the blade such that themonomer liquid can flow through the tube (141) in the direction of thecement powder cartridge (133). It is advantageous for the edge of thetube (140) that has the film pouch (132) rest on it to be provided as abroad, flat edge. This allows the film pouch (132) to be glued directlyonto the tube (140) using an adhesive or two-sided, ring-shaped adhesivetape. This can attain tight connection of the film pouch (132) to theedge of the tube (140).

The scope of the invention also includes a prepack vacuum cementingsystem that contains at least one cement powder-filled cement powdercartridge (133) having at least one mixing organ (136) and a vacuumconnection (143), at least one monomer liquid-filled film pouch (132)and at least one plunger (9, 19, 39, 59, 79, 99), whereby the plunger(9, 19, 39, 59, 79, 99) is provided as a tube, whereby a mandrel (141)having a tip or a mandrel (141) having a blade is arranged on the insideof the tube (140) and has its tip situated below the edge of the tube(140), in that at least one external side of the film pouch (132) restson the edge of the tube (140), and in that at least one vacuumconnection is present, whereby the vacuum connection is concurrentlyprovided as opening (6, 36, 56, 76, 96) for fluids.

The features of the invention disclosed in the preceding description andin the claims, figures, and exemplary embodiments, can be essential forthe implementation of the various embodiments of the invention bothalone and in any combination.

LIST OF REFERENCE NUMBERS

-   1, 31, 51, 71, 91, 111, 131 Container-opening system-   2, 32, 52, 72, 92, 132 Container-   3, 33, 53, 73, 93 Container head-   4, 34, 54, 74, 94 Chamber-   5, 55, 75 Connector-   6, 36, 56, 76, 96 Outlet opening-   7, 97 Lid-   8, 38, 58, 98 Open walls-   9, 19, 39, 59, 79, 99 Plunger-   20 Fork-shaped guidance/fin-   21 Bevelled plate-   40, 60 Lever-   41 First lever arm/centre of rotation-   42 Second lever arm-   61 Lever end/centre of rotation-   63 Wedge-shaped fin-   80 Fin/bevelling-   100 Bracketing-   110, 130 Vacuum cementing system-   112 Connecting means-   113, 133 Cement powder cartridge-   114 Fastening means-   115 Foot part-   116, 136 Feed plunger-   140 Tube-   141 Mandrel-   142 Application opening-   143 Vacuum connection

The invention claimed is:
 1. A vacuum cementing system comprising atleast one cement powder cartridge and an container-opening systemconnected via a tube having an inside and a cross-section, wherein theat least one cement powder cartridge is provided at a first side of thetube, the vacuum cementing system comprising: a film pouch for at leastone liquid and/or at least one powder provided at a second side of thetube opposite the first side of the tube and having a flexible wall,wherein the flexible wall contacts against the tube in a gas-tightmanner; an opening device of the container-open system arranged on theinside of the tube, wherein the opening device comprises a mandrel or ablade attached to one wall of the tube; and an outlet opening forapplying a negative pressure, wherein, when a negative pressure is beingapplied to the outlet opening, the film pouch, that is mobile withrespect to the opening device, is pulled into the inside of the tube andopened by the opening device such that the film pouch itself moves, bythe flexible wall contacting against the cross-section of the tube, ontothe opening device, and further wherein, when the vacuum cementingsystem is located in the upright position, the film pouch, in itsentirety, is offset with respect to a vertically extending plane definedby the at least one cement powder cartridge.
 2. The vacuum cementingsystem according to claim 1, wherein the at least one cement powdercartridge comprises a feed plunger.
 3. The vacuum cementing systemaccording to claim 1, wherein the at least one cement powder cartridgecomprises at least one mixing organ.
 4. The vacuum cementing systemaccording to claim 1 further comprising: an application opening providedat a first end of the at least one cement powder cartridge that isopposite with respect to the opening device provided at an oppositesecond end of the at least one cement powder cartridge.